LIDAR with Co-Aligned Transmit and Receive Paths

This application is a continuation of U.S. patent application Ser. No. 18/463,637, filed Sep. 8, 2023, which is a continuation of U.S. patent application Ser. No. 17/137,299, filed Dec. 29, 2020, which is a continuation of U.S. patent application Ser. No. 15/695,755, filed Sep. 5, 2017. The foregoing applications are incorporated herein by reference.

Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.

Light detectors, such as photodiodes, single photon avalanche diodes (SPADs), or other types of avalanche photodiodes (APDs), can be used to detect light that is imparted on their surfaces (e.g., by outputting an electrical signal, such as a voltage or a current, that indicates an intensity of the light). Many types of such devices are fabricated out of semiconducting materials, such as silicon. In order to detect light over a large geometric area, multiple light detectors can be arranged as an array. These arrays are sometimes referred to as silicon photomultipliers (SiPMs) or multi-pixel photon counters (MPPCs).

Some of the above arrangements are sensitive to relatively low intensities of light, thereby enhancing their detection qualities. However, this can lead to the above arrangements also being disproportionately susceptible to adverse background effects (e.g., extraneous light from outside sources could affect a measurement by the light detectors).

In one example, a system comprises a light source that emits light. The system also comprises a waveguide that guides the emitted light from a first side of the waveguide to a second side of the waveguide opposite the first side. The waveguide has a third side extending between the first side and the second side. The system also comprises a mirror that reflects the guided light toward the third side of the waveguide. At least a portion of the reflected light propagates out of the waveguide toward a scene. The system also comprises a light detector. The system also comprises a lens that focuses light from the scene toward the waveguide and the light detector.

In another example, a system comprises a light source that emits light. The system also comprises a waveguide having an input end and one or more output ends opposite the input end. The waveguide guides the emitted light from the input end to the one or more output ends. The waveguide has a given side that extends from the input end to the one or more output ends. The system also comprises one or more mirrors that reflect at least a portion of the guided light toward the given side of the waveguide. The reflected light propagates out of the waveguide. The system also comprises a lens that directs, toward a scene, the reflected light propagating out of the waveguide. The system also comprises one or more arrays of light detectors. The lens focuses light from the scene toward the waveguide and the one or more arrays of light detectors.

In yet another example, method involves emitting light toward a first side of a waveguide. The method also involves guiding, inside a waveguide, the emitted light from the first side to a second side of the waveguide opposite the first side. The method also involves reflecting the guided light toward a third side of the waveguide. At least portion of the reflected light propagates out of the third side of the waveguide toward a scene. The method also involves focusing, via a lens, light from the scene onto the waveguide and a light detector.

In still another example, a system comprises means for emitting light toward a first side of a waveguide. The system also comprises means for guiding, inside a waveguide, the emitted light from the first side to a second side of the waveguide opposite the first side. The system also comprises means for reflecting the guided light toward a third side of the waveguide. At least portion of the reflected light propagates out of the third side of the waveguide toward a scene. The system also comprises means for focusing, via a lens, light from the scene onto the waveguide and a light detector.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the figures and the following detailed description.

Any example embodiment or feature described herein is not necessarily to be construed as preferred or advantageous over other embodiments or features. The example embodiments described herein are not meant to be limiting. It will be readily understood that certain aspects of the disclosed implementations can be arranged and combined in a wide variety of different configurations. Furthermore, the particular arrangements shown in the figures should not be viewed as limiting. It should be understood that other implementations might include more or less of each element shown in a given figure. In addition, some of the illustrated elements may be combined or omitted. Similarly, an example implementation may include elements that are not illustrated in the figures.

Example implementations may relate to devices, systems, and methods that involve detecting light using one or more light detectors. In some examples, the light detectors may be a sensing component of a light detection and ranging (LIDAR) device.

One example system includes a lens. The lens may be used to focus light from a scene. However, the lens may also focus background light not intended to be observed by the system (e.g., sunlight). In order to selectively filter the light (i.e., separate background light from light corresponding to information within the scene), an opaque material (e.g., selectively etched metal, a glass substrate partially covered by a mask, etc.) may be placed behind the lens. The opaque material could be shaped as a slab, a sheet, or various other shapes in a variety of embodiments. Within the opaque material, an aperture may be defined. With this arrangement, a portion of, or the entirety of, the light focused by the lens could be selected for transmission through the aperture.

In the direction of propagation of the light transmitted through the aperture, the system may include an array of light detectors (e.g., SPADs, etc.) arranged to detect at least a portion of the focused light transmitted through the aperture.

The system may also include a light source that emits light, and a waveguide that receives the emitted light at an input end of the waveguide. The waveguide guides the emitted light from the input end to an output end of the waveguide opposite the input end. The waveguide has a given side that extends from the input end to the output end. The waveguide transmits at least a portion of the emitted light out of the given side and toward the lens. In general, the output end of the waveguide may be positioned along a propagation path of the focused light propagating from the lens to the array of light detectors. In one embodiment, the emitted light transmitted out of the waveguide may propagate through the same aperture through which the focused light is transmitted toward the array of light detectors.

To facilitate propagation of the guided light out of the given side of the waveguide, in some examples, the system may include a mirror disposed along a propagation path of the guided light propagating inside the waveguide. The mirror may be tilted toward the given side of the waveguide. As such, the mirror may reflect the guided light (or a portion thereof) toward a particular region of the given side that is co-aligned with the path of the focused light propagating toward the array of light detectors. For example, the particular region may be adjacent to the aperture defined by the opaque material.

Thus, in one example arrangement, the system may illuminate the scene by directing the emitted light according to a transmit path that extends through the waveguide, aperture, and lens. The system may also receive reflections of the emitted light from the illuminated scene according to a receive path that extends through the same lens and aperture. The transmit and receive paths of the light in this example could thus be co-aligned (e.g., associated with same or similar respective fields-of-view).

Because the transmit path is spatially aligned with the receive path, the example system may reduce (or prevent) optical scanning distortions associated with parallax. For instance, if the transmit and receive paths were instead to be spatially offset relative to one another (e.g., have different respective viewing or pointing directions, etc.), a scanned representation of the scene could be affected by optical distortions such as parallax.

Other aspects, features, implementations, configurations, arrangements, and advantages are possible as well.

1 FIG.A 100 100 110 112 114 120 120 130 100 102 198 102 130 100 100 130 110 a is an illustration of a systemthat includes an aperture, according to example embodiments. As shown, systemincludes an arrayof light detectors (exemplified by detectorsand), an aperturedefined within an opaque material, and a lens. Systemmay measure lightreflected or scattered by an objectwithin a scene. In some instances, lightmay also include light propagating directly from background sources (not shown) toward lens. In some examples, systemmay be included in a light detection and ranging (LIDAR) device. For example, the LIDAR device may be used for navigation of an autonomous vehicle. Further, in some embodiments, system, or portions thereof, may be contained within an area that is unexposed to exterior light other than through lens. This may reduce an amount of ambient light (which may affect measurements) reaching the detectors in array.

110 112 114 110 110 110 110 110 120 110 110 120 120 130 120 130 110 110 120 110 a a a a a Arrayincludes an arrangement of light detectors, exemplified by detectorsand. In various embodiments, arraymay have different shapes. As shown, arrayhas a rectangular shape. However, in other embodiments, arraymay be circular or may have a different shape. The size of arraymay be selected according to an expected cross-sectional area of lightdiverging from aperture. For example, the size of arraymay be based on the distance between arrayand aperture, the distance between apertureand lens, dimensions of aperture, optical characteristics of lens, among other factors. In some embodiments, arraymay be movable. For example, the location of arraymay be adjustable so as to be closer to, or further from, aperture. To that end, for instance, arraycould be mounted on an electrical stage capable of translating in one, two, or three dimensions.

110 110 102 110 198 198 100 110 110 110 102 110 1 FIG.A Further, in some implementations, arraymay provide one or more outputs to a computing device or logic circuitry. For example, a microprocessor-equipped computing device may receive electrical signals from arraywhich indicate an intensity of lightincident on array. The computing device may then use the electrical signals to determine information about object(e.g., distance between objectand system, etc.). In some embodiments, some or all of the light detectors within arraymay be interconnected with one another in parallel. To that end, for example, arraymay be a SiPM or an MPPC, depending on the particular arrangement and type of the light detectors within array. By connecting the light detectors in a parallel circuit configuration, for instance, the outputs from the light detectors can be combined to effectively increase a detection area in which a photon in lightcan be detected (e.g., shaded region of arrayshown in).

112 114 112 114 112 114 112 114 Light detectors,, etc., may include various types of light detectors. In one example, detectors,, etc., include SPADs. SPADs may employ avalanche breakdown within a reverse biased p-n junction (i.e., diode) to increase an output current for a given incident illumination on the SPAD. Further, SPADs may be able to generate multiple electron-hole pairs for a single incident photon. In another example, light detectors,, etc., may include linear-mode avalanche photodiodes (APDs). In some instances, APDs or SPADs may be biased above an avalanche breakdown voltage. Such a biasing condition may create a positive feedback loop having a loop gain that is greater than one. Further, SPADs biased above the threshold avalanche breakdown voltage may be single photon sensitive. In other examples, light detectors,, etc., may include photoresistors, charge-coupled devices (CCDs), photovoltaic cells, and/or any other type of light detector.

110 110 102 110 110 110 112 114 110 In some implementations, arraymay include more than one type of light detector across the array. For example, arraycan be configured to detect multiple predefined wavelengths of light. To that end, for instance, arraymay comprise some SPADs that are sensitive to one range of wavelengths and other SPADs that are sensitive to a different range of wavelengths. In some embodiments, light detectorsmay be sensitive to wavelengths between 400 nm and 1.6 μm (visible and/or infrared wavelengths). Further, light detectorsmay have various sizes and shapes within a given embodiment or across various embodiments. In some embodiments, light detectors,, etc., may include SPADs that have package sizes that are 1%, .1%, or .01% of the area of array.

120 102 130 110 120 110 120 112 114 120 120 120 120 120 130 a Opaque material(e.g., mask, etc.) may block a portion of lightfrom the scene (e.g., background light) that is focused by the lensfrom being transmitted to array. For example, opaque materialmay be configured to block certain background light that could adversely affect the accuracy of a measurement performed by array. Alternatively or additionally, opaque materialmay block light in the wavelength range detectable by detectors,, etc. In one example, opaque materialmay block transmission by absorbing a portion of incident light. In another example, opaque materialmay block transmission by reflecting a portion of incident light. A non-exhaustive list of example implementations of opaque materialincludes an etched metal, a polymer substrate, a biaxially-oriented polyethylene terephthalate (BoPET) sheet, or a glass overlaid with an opaque mask, among other possibilities. In some examples, opaque material, and therefore aperture, may be positioned at or near a focal plane of lens.

120 120 102 120 120 120 120 120 120 120 112 114 120 120 120 120 102 120 120 a a a a a a a a a Apertureprovides a port within opaque materialthrough which light(or a portion thereof) may be transmitted. Aperturemay be defined within opaque materialin a variety of ways. In one example, opaque material(e.g., metal, etc.) may be etched to define aperture. In another example, opaque materialmay be configured as a glass substrate overlaid with a mask, and the mask may include a gap that defines aperture(e.g., via photolithography, etc.). In various embodiments, aperturemay be partially or wholly transparent, at least to wavelengths of light that are detectable by light detectors,, etc. For example, where opaque materialis a glass substrate overlaid with a mask, aperturemay be defined as a portion of the glass substrate not covered by the mask, such that apertureis not completely hollow but rather made of glass. Thus, in some instances, aperturemay be nearly, but not entirely, transparent to one or more wavelengths of light(e.g., glass substrates are typically not 100% transparent). Alternatively, in some instances, aperturemay be formed as a hollow region of opaque material.

120 120 102 102 120 120 110 120 120 120 130 110 110 a a a a a 2 2 2 In some examples, aperture(in conjunction with opaque material) may be configured to spatially filter lightfrom the scene at the focal plane. To that end, for example, lightmay be focused onto a focal plane along a surface of opaque material, and aperturemay allow only a portion of the focused light to be transmitted to array. As such, aperturemay behave as an optical pinhole. In one embodiment, aperturemay have a cross-sectional area of between .02 mmand .06 mm(e.g., .04 mm). In other embodiments, aperturemay have a different cross-sectional area depending on various factors such as optical characteristics of lens, distance to array, noise rejection characteristics of the light detectors in array, etc.

120 a Thus, although the term “aperture” as used above with respect to aperturemay describe a recess or hole in an opaque material through which light may be transmitted, it is noted that the term “aperture” may include a broad array of optical features. In one example, as used throughout the description and claims, the term “aperture” may additionally encompass transparent or translucent structures defined within an opaque material through which light can be at least partially transmitted. In another example, the term “aperture” may describe a structure that otherwise selectively limits the passage of light (e.g., through reflection or refraction), such as a mirror surrounded by an opaque material. In one example embodiment, mirror arrays surrounded by an opaque material may be arranged to reflect light in a certain direction, thereby defining a reflective portion, which may be referred to as an “aperture”.

120 120 120 100 102 130 110 102 a a a Although apertureis shown to have a rectangular shape, it is noted that aperturecan have a different shape, such as a round shape, circular shape, elliptical shape, among others. In some examples, aperturecan alternatively have an irregular shape specifically designed to account for optical aberrations within system. For example, a keyhole shaped aperture may assist in accounting for parallax occurring between an emitter (e.g., light source that emits light) and a receiver (e.g., lensand array). The parallax may occur if the emitter and the receiver are not located at the same position, for example. Other irregular aperture shapes are also possible, such as specifically shaped apertures that correspond with particular objects expected to be within a particular scene or irregular apertures that select specific polarizations of light(e.g., horizontal or vertical polarizations).

130 102 120 130 102 102 130 130 100 130 102 130 120 a Lensmay focus lightfrom the scene onto the focal plane where apertureis positioned. With this arrangement, the light intensity collected from the scene, at lens, may be focused to have a reduced cross-sectional area over which lightis projected (i.e., increasing the spatial power density of light). For example, lensmay include a converging lens, a biconvex lens, and/or a spherical lens, among other examples. Alternatively, lenscan be implemented as a consecutive set of lenses positioned one after another (e.g., a biconvex lens that focuses light in a first direction and an additional biconvex lens that focuses light in a second direction). Other types of lenses and/or lens arrangements are also possible. In addition, systemmay include other optical elements (e.g., mirrors, etc.) positioned near lensto aid in focusing lightincident on lensonto opaque material.

198 100 100 198 102 198 Objectmay be any object positioned within a scene surrounding system. In implementations where systemis included in a LIDAR device, objectmay be illuminated by a LIDAR transmitter that emits light (a portion of which may return as light). In example embodiments where the LIDAR device is used for navigation on an autonomous vehicle, objectmay be or include pedestrians, other vehicles, obstacles (e.g., trees, debris, etc.), or road signs, among others.

102 198 130 120 120 110 198 102 110 a As noted above, lightmay be reflected or scattered by object, focused by lens, transmitted through aperturein opaque material, and measured by light detectors in array. This sequence may occur (e.g., in a LIDAR device) to determine information about object. In some embodiments, lightmeasured by arraymay additionally or alternatively include light reflected or scattered off multiple objects, transmitted by a transmitter of another LIDAR device, ambient light, sunlight, among other possibilities.

102 198 130 198 100 102 102 102 102 In some examples, the wavelength(s) of lightused to analyze objectmay be selected based on the types of objects expected to be within a scene and their expected distance from lens. For example, if an object expected to be within the scene absorbs all incoming light of 500 nm wavelength, a wavelength other than 500 nm may be selected to illuminate objectand to be analyzed by system. The wavelength of light(e.g., if transmitted by a transmitter of a LIDAR device) may be associated with a source that generates light(or a portion thereof). For example, if the light is generated by a laser diode, lightmay comprise light within a wavelength range that includes 900 nm (or other infrared and/or visible wavelength). Thus, various types of light sources are possible for generating light(e.g., an optical fiber amplifier, various types of lasers, a broadband source with a filter, etc.).

102 120 110 102 120 a a 2 As shown, lightdiverges as it propagates away from aperture. Due to the divergence, a detection area at array(e.g., shown as shaded area illuminated by light) may be larger than a cross-sectional area of aperture. An increased detection area (e.g., measured in m) for a given light power (e.g., measured in W) may lead to a reduced light intensity (e.g., measured in

110 incident on array.

110 110 110 The reduction in light intensity may be particularly beneficial in embodiments where arrayincludes SPADs or other light detectors having high sensitivities. For example, SPADs derive their sensitivity from a large reverse-bias voltage that produces avalanche breakdown within a semiconductor. This avalanche breakdown can be triggered by the absorption of a single photon, for example. Once a SPAD absorbs a single photon and the avalanche breakdown begins, the SPAD cannot detect additional photons until the SPAD is quenched (e.g., by restoring the reverse-bias voltage). The time until the SPAD is quenched may be referred to as the recovery time. If additional photons are arriving at time intervals approaching the recovery time (e.g., within a factor of ten), the SPAD may begin to saturate, and the measurements by the SPAD may thus become less reliable. By reducing the light power incident on any individual light detector (e.g., SPAD) within array, the light detectors (e.g., SPADs) in arraymay remain unsaturated. As a result, the light measurements by each individual SPAD may have an increased accuracy.

1 FIG.B 100 100 132 140 132 132 140 132 110 132 102 140 132 110 is another illustration of system. As shown, systemalso includes a light filterand a light emitter. Filtermay include any optical filter configured to selectively transmit light within a predefined wavelength range. For example, filtercan be configured to selectively transmit light within a visible wavelength range, an infrared wavelength range, or any other wavelength range of the light signal emitted by emitter. For example, optical filtermay be configured to attenuate light of particular wavelengths or divert light of particular wavelengths away from the array. For instance, optical filtermay attenuate or divert wavelengths of lightthat are outside of the wavelength range emitted by emitter. Therefore, optical filtermay, at least partially, reduce ambient light or background light from adversely affecting measurements by array.

132 110 132 130 120 132 130 198 120 110 110 110 132 110 120 120 130 130 130 a a In various embodiments, optical filtermay be located in various positions relative to array. As shown, optical filteris located between lensand opaque material. However, optical filtermay alternatively be located between lensand object, between opaque materialand array, combined with array(e.g., arraymay have a surface screen that optical filter, or each of the light detectors in arraymay individually be covered by a separate optical filter, etc.), combined with aperture(e.g., aperturemay be transparent only to a particular wavelength range, etc.), or combined with lens(e.g., surface screen disposed on lens, material of lenstransparent only to a particular wavelength range, etc.), among other possibilities.

1 FIG.B 140 110 140 140 198 110 140 As shown in, light emitteremits a light signal to be measured by array. Emittermay include a laser diode, fiber laser, a light-emitting diode, a laser bar, a nanostack diode bar, a filament, a LIDAR transmitter, or any other light source. As shown, emittermay emit light which is reflected by objectin the scene and ultimately measured (at least a portion thereof) by array. In some embodiments, emittermay be implemented as a pulsed laser (as opposed to a continuous wave laser), allowing for increased peak power while maintaining an equivalent continuous power output.

2 FIG.A 200 200 298 200 238 240 140 290 100 294 296 290 210 220 230 110 120 130 200 200 132 290 100 is a simplified block diagram of a LIDAR device, according to example embodiments. In some example embodiments, LIDAR devicecan be mounted to a vehicle and employed to map a surrounding environment (e.g., the scene including object, etc.) of the vehicle. As shown, LIDAR deviceincludes a controller,, a laser emitterthat may be similar to emitter, and a noise limiting systemthat may be similar to system, a rotating platform, and one or more actuators. Systemincludes an arrayof light detectors, an opaque materialwith an aperture defined therein (not shown), and a lens, which can be similar, respectively, to array, opaque material, and lens. It is noted that LIDAR devicemay alternatively include more or fewer components than those shown. For example, LIDAR devicemay include an optical filter (e.g., filter). Thus, systemcan be implemented similarly to systemand/or any other noise limiting system described herein.

200 240 202 298 140 102 198 100 240 200 200 200 202 298 210 290 200 Devicemay operate emitterto emit lighttoward a scene that includes object, similarly to, respectively, emitter, light, and objectof device. To that end, in some implementations, emitter(and/or one or more other components of device) can be configured as a LIDAR transmitter of LIDAR device. Devicemay then detect reflections of lightfrom the scene to map or otherwise determine information about object. To that end, in some implementations, array(and/or one or more other components of system) can be configured as a LIDAR receiver of LIDAR device.

238 200 238 200 200 238 Controllermay be configured to control one or more components of LIDAR deviceand to analyze signals received from the one or more components. To that end, controllermay include one or more processors (e.g., a microprocessor, etc.) that execute instructions stored in a memory (not shown) of deviceto operate device. Additionally or alternatively, controllermay include digital or analog circuitry wired to perform one or more of the various functions described herein.

294 200 202 294 200 290 240 294 294 200 200 294 200 294 Rotating platformmay be configured to rotate about an axis to adjust a pointing direction of LIDAR(e.g., direction of emitted lightrelative to the environment, etc.). To that end, rotating platformcan be formed from any solid material suitable for supporting one or more components of LIDAR. For example, system(and/or emitter) may be supported (directly or indirectly) by rotating platformsuch that each of these components moves relative to the environment while remaining in a particular relative arrangement in response to rotation of rotating platform. In particular, the mounted components could be rotated (simultaneously) about an axis so that LIDARmay adjust its pointing direction while scanning the surrounding environment. In this manner, a pointing direction of LIDARcan be adjusted horizontally by actuating rotating platformto different directions about the axis of rotation. In one example, LIDARcan be mounted on a vehicle, and rotating platformcan be rotated to scan regions of the surrounding environment at various directions from the vehicle.

294 296 294 296 In order to rotate platformin this manner, one or more actuatorsmay actuate rotating platform. To that end, actuatorsmay include motors, pneumatic actuators, hydraulic pistons, and/or piezoelectric actuators, among other possibilities.

238 296 294 294 294 200 294 With this arrangement, controllercould operate actuator(s)to rotate rotating platformin various ways so as to obtain information about the environment. In one example, rotating platformcould be rotated in either direction about an axis. In another example, rotating platformmay carry out complete revolutions about the axis such that LIDARscans a 360° field-of-view (FOV) of the environment. In yet another example, rotating platformcan be rotated within a particular range (e.g., by repeatedly rotating from a first angular position about the axis to a second angular position and back to the first angular position, etc.) to scan a narrower FOV of the environment. Other examples are possible.

294 200 200 200 296 294 Moreover, rotating platformcould be rotated at various frequencies so as to cause LIDARto scan the environment at various refresh rates. In one embodiment, LIDARmay be configured to have a refresh rate of 10 Hz. For example, where LIDARis configured to scan a 360° FOV, actuator(s)may rotate platformfor ten complete rotations per second.

2 FIG.B 200 200 231 240 200 illustrates a perspective view of LIDAR device. As shown, devicealso includes a transmitter lensthat directs emitted light from emittertoward the environment of device.

2 FIG.B 200 240 290 231 230 200 240 290 202 200 240 202 290 To that end,illustrates an example implementation of devicewhere emitterand systemeach have separate respective optical lensesand. However, in other embodiments, devicecan be alternatively configured to have a single shared lens for both emitterand system. By using a shared lens to both direct the emitted light and receive the incident light (e.g., light), advantages with respect to size, cost, and/or complexity can be provided. For example, with a shared lens arrangement, devicecan mitigate parallax associated with transmitting light (by emitter) from a different viewpoint than a viewpoint from which lightis received (by system).

2 FIG.B 240 231 200 200 202 200 202 230 200 As shown in, light beams emitted by emitterpropagate from lensalong a pointing direction of LIDARtoward an environment of LIDAR, and may then reflect off one or more objects in the environment as light. LIDARmay then receive reflected light(e.g., through lens) and provide data pertaining to the one or more objects (e.g., distance between the one or more objects and the LIDAR, etc.).

2 FIG.B 294 290 240 294 201 290 240 200 200 201 200 200 200 201 Further, as shown in, rotating platformmounts systemand emitterin the particular relative arrangement shown. By way of example, if rotating platformrotates about axis, the pointing directions of systemand emittermay simultaneously change according to the particular relative arrangement shown. Through this process, LIDARcan scan different regions of the surrounding environment according to different pointing directions of LIDARabout axis. Thus, for instance, device(and/or another computing system) can determine a three-dimensional map of a 360° (or less) view of the environment of deviceby processing data associated with different pointing directions of LIDARabout axis.

201 200 290 240 201 In some examples, axismay be substantially vertical. In these examples, the pointing direction of devicecan be adjusted horizontally by rotating system(and emitter) about axis.

290 240 201 200 200 290 240 200 In some examples, system(and emitter) can be tilted (relative to axis) to adjust the vertical extents of the FOV of LIDAR. By way of example, LIDAR devicecan be mounted on top of a vehicle. In this example, system(and emitter) can be tilted (e.g., toward the vehicle) to collect more data points from regions of the environment that are closer to a driving surface on which the vehicle is located than data points from regions of the environment that are above the vehicle. Other mounting positions, tilting configurations, and/or applications of LIDAR deviceare possible as well (e.g., on a different side of the vehicle, on a robotic device, or on any other mounting surface).

200 2 FIG.B It is noted that the shapes, positions, and sizes of the various components of devicecan vary, and are illustrated as shown inonly for the sake of example.

2 FIG.A 238 210 200 298 240 238 210 238 200 298 294 240 202 290 200 200 Returning now to, in some implementations, controllermay use timing information associated with a signal measured by arrayto determine a location (e.g., distance from LIDAR device) of object. For example, in embodiments where emitteris a pulsed laser, controllercan monitor timings of output light pulses and compare those timings with timings of signal pulses measured by array. For instance, controllercan estimate a distance between deviceand objectbased on the speed of light and the time of travel of the light pulse (which can be calculated by comparing the timings). In one implementation, during the rotation of platform, emittermay emit light pulses (e.g., light), and systemmay detect reflections of the emitted light pulses. Device(or another computer system that processes data from device) can then generate a three-dimensional (3D) representation of the scanned environment based on a comparison of one or more characteristics (e.g., timing, pulse length, light intensity, etc.) of the emitted light pulses and the detected reflections thereof.

238 240 230 238 210 In some implementations, controllermay be configured to account for parallax (e.g., due to laser emitterand lensnot being located at the same location in space). By accounting for the parallax, controllercan improve accuracy of the comparison between the timing of the output light pulses and the timing of the signal pulses measured by the array.

238 202 240 238 240 294 240 238 202 240 238 200 132 202 200 210 220 230 In some implementations, controllercould modulate lightemitted by emitter. For example, controllercould change the projection (e.g., pointing) direction of emitter(e.g., by actuating a mechanical stage, such as platformfor instance, that mounts emitter). As another example, controllercould modulate the timing, the power, or the wavelength of lightemitted by emitter. In some implementations, controllermay also control other operational aspects of device, such as adding or removing filters (e.g., filter) along a path of propagation of light, adjusting relative positions of various components of device(e.g., array, opaque material(and an aperture therein), lens, etc.), among other possibilities.

238 220 230 220 238 230 238 In some implementations, controllercould also adjust an aperture (not shown) within material. In some embodiments, the aperture may be selectable from a number of apertures defined within the opaque material. In such embodiments, a MEMS mirror could be located between lensand opaque materialand may be adjustable by controllerto direct the focused light from lensto one of the multiple apertures. In some embodiments, the various apertures may have different shapes and sizes. In still other embodiments, the aperture may be defined by an iris (or other type of diaphragm). The iris may be expanded or contracted by controller, for example, to control the size or shape of the aperture.

200 290 298 238 290 290 202 230 238 202 238 210 210 202 210 110 110 1 FIG.A Thus, in some examples, LIDAR devicecan modify a configuration of systemto obtain additional or different information about objectand/or the scene. In one example, controllermay select a larger aperture in response to a determination that background noise received by systemfrom the scene is currently relatively low (e.g., during night-time). The larger aperture, for instance, may allow systemto detect a portion of lightthat would otherwise be focused by lensoutside the aperture. In another example, controllermay select a different aperture position to intercept the portion of light. In yet another example, controllercould adjust the distance between an aperture and light detector array. By doing so, for instance, the cross-sectional area of a detection region in array(i.e., cross-sectional area of lightat array) can be adjusted as well. For example, in, the detection region of arrayis indicated by shading on array.

290 200 290 110 102 120 110 110 100 110 120 100 1 FIG.A a a However, in some scenarios, the extent to which the configuration of systemcan be modified may depend on various factors such as a size of LIDAR deviceor system, among other factors. For example, referring back to, a size of arraymay depend on an extent of divergence of lightfrom a location of apertureto a location of array. Thus, for instance, the maximum vertical and horizontal extents of arraymay depend on the physical space available for accommodating systemwithin a LIDAR device. Similarly, for instance, an available range of values for the distance between arrayand aperturemay also be limited by physical limitations of a LIDAR device where systemis employed. Accordingly, example implementations are described herein for space-efficient noise limiting systems that increase a detection area in which light detectors can intercept light from the scene and reduce background noise.

240 230 298 202 240 202 230 200 240 290 200 230 In some scenarios, where emitterand lenshave different physical locations, the scanned representation of objectmay be susceptible to parallax associated with a spatial offset between the transmit path of lightemitted by emitterand the receive path of reflected lightincident on lens. Accordingly, example implementations are described herein for reducing and/or mitigating the effects of such parallax. In one example, devicemay alternatively include emitterwithin systemsuch that the LIDAR transmit and receive paths of LIDARare co-aligned (e.g., both paths propagate through lens).

200 It is noted that the various functional blocks shown for the components of devicecan be redistributed, rearranged, combined, and/or separated in various ways different than the arrangement shown.

3 FIG.A 300 360 300 200 240 290 300 302 398 100 102 198 300 310 320 320 330 340 110 120 120 130 140 320 120 a a a a is an illustration of a systemthat includes a waveguide, according to example embodiments. In some implementations, systemcan be used with deviceinstead of or in addition to transmitterand system. As shown, systemmay measure lightreflected by an objectwithin a scene similarly to, respectively, system, light, and object. Further, as shown, systemincludes a light detector array, an opaque material, an aperture, a lens, and a light source, which may be similar, respectively, to array, material, aperture, lens, and emitter. For the sake of example, apertureis shown to have a different shape (elliptical) than a shape of aperture(rectangular). Other aperture shapes are possible.

300 360 302 320 302 360 302 310 a As shown, systemalso includes waveguide(e.g., optical waveguide, etc.) arranged along a propagation path of focused light(transmitted through aperture). For example, as shown, a first portion of focused lightis projected onto waveguide(e.g., shaded region) and a second portion of focused lightis projected onto array.

3 FIG.B 3 FIG.B 3 3 FIGS.A andB 300 302 330 310 360 360 304 340 360 360 a illustrates a cross-section view of system. As best shown in, at least a portion of focused lightmay propagate from lensto arraywithout propagating through waveguide. As shown in, waveguideis arranged to receive emitted lightemitted by light sourceand projected onto sideof waveguide.

360 304 360 360 360 360 360 304 360 360 360 360 360 360 a b a c d To that end, waveguidecan be formed from a glass substrate (e.g., glass plate, etc.), a photoresist material (e.g., SU-8, etc.), or any other material at least partially transparent to one or more wavelengths of light. Further, in some examples, waveguidemay be formed from a material that has a different index of refraction than materials surrounding waveguide. Thus, waveguidemay guide at least a portion of light propagating therein via internal reflection (e.g., total internal reflection, frustrated total internal reflection, etc.) at one or more edges, sides, walls, etc., of waveguide. For example, waveguidemay guide emitted lightincident on sidetoward side(opposite to side) via internal reflection at sides,, and/or other sides along a length of waveguide.

3 3 FIGS.A andB 300 350 350 304 Further, as shown in, systemalso includes a mirror. Mirrormay include any reflective material that has reflectivity characteristics suitable for reflecting (at least partially) wavelengths of light. To that end, a non-exhaustive list of example reflective materials includes gold, aluminum, other metal or metal oxide, synthetic polymers, hybrid pigments (e.g., fibrous clays and dyes, etc.), among other examples.

350 360 390 360 360 392 360 360 390 350 360 390 350 392 360 360 350 304 360 360 360 350 360 360 360 390 360 360 392 360 360 350 360 350 360 360 360 a c a c c a c a b b c b c a b a b Mirrormay be tilted (e.g., as compared to an orientation of side) at an offset angletoward sideof waveguide. For example, an anglebetween sideand sidemay be greater than anglebetween mirrorand side. In one embodiment, offset or tilting angleof mirroris 45°, and anglebetween sideand sideis 90°. However, other angles are possible. In general, mirroris positioned along a path of at least a portion of guided lightpropagating inside waveguide(received at sideand guided toward side). In the embodiment shown, mirroris disposed on sideof waveguide. For instance, waveguidecan be formed such that anglebetween sideand sideis different than anglebetween sideand side. Mirrorcan then be disposed on side(e.g., via chemical vapor deposition, sputtering, mechanical coupling, or another process). However, in other embodiments, mirrorcan be alternatively disposed inside waveguide(e.g., between sidesand).

360 304 360 360 360 360 360 360 360 360 304 360 360 360 360 360 360 360 360 360 360 360 304 b a b c c c c c d c d 3 FIG.B 3 FIG.B As noted above, waveguidemay guide at least a portion of emitted light, via total internal reflection for instance, inside waveguidetoward side. For example, as best shown in, waveguidemay extend vertically (e.g., lengthwise) between sidesand. In some examples, sidemay correspond to an interface between a relatively high index of refraction medium (e.g., photoresist, epoxy, etc.) of waveguideand a relatively lower index of refraction medium (e.g., air, vacuum, optical adhesive, glass, etc.) adjacent to side. Thus, for instance, if guided lightpropagates to sideat less than the critical angle (e.g., which may be based on a ratio of indexes of refractions of the adjacent materials at side, etc.), then the guided light incident on side(or a portion thereof) may be reflected back into waveguide. Similarly, guided light incident on sideat less than the critical angle may also be reflected back into waveguide. Thus, waveguidemay control divergence of guided light via internal reflection at sidesand, for example. Similarly, waveguidemay extend through the page in the illustration ofbetween two opposite sides of waveguideto control divergence of guided light.

304 360 360 350 360 304 360 360 390 304 350 360 304 360 360 320 360 304 330 330 304 a b b c c c a c Thus, at least a portion of emitted light(received at side) may reach tilted side. Mirror(e.g., disposed on side) may then reflect the at least portion of guided lighttoward sideand out of waveguide. For example, offset or tilting anglecan be selected such that reflected lightfrom mirrorpropagates toward a particular region of sideat greater than the critical angle. As a result, reflected lightmay be (at least partially) transmitted through siderather than reflected (e.g., via total internal reflection etc.) back into waveguide. Further, in the embodiment shown, aperturecould be located adjacent to the particular region of side, and may thus transmit lighttoward lens. Lensmay then direct lighttoward a scene.

304 398 330 302 330 302 320 a. Emitted lightmay then reflect off one or more objects (e.g., object) in the scene, and return to lens(e.g., as part of lightfrom the scene). Lensmay then focus light(including the reflections of the emitted light beams) through aperture

3 FIG.A 302 360 302 360 360 360 360 310 350 302 350 310 360 350 320 302 350 302 350 360 310 350 302 350 310 c d a As best shown in, a first portion of focused lightmay be focused onto waveguide(e.g., shaded region). In some instances, the first portion of focused lightmay propagate through transparent regions of waveguide(e.g., from sideto sideand then out of waveguidetoward array, without being intercepted by mirror. However, in some examples, the first portion of focused lightmay be at least partially intercepted by mirrorand then reflected away from array(e.g., guided inside waveguide, etc.). To mitigate this, in some implementations, mirrorcan be configured to have a small size relative to apertureand/or a projection area of focused lightat the location of mirror. In these examples, a larger portion of focused lightmay propagate adjacent to mirror(and/or waveguide) to continue propagating toward array. Alternatively, mirrorcan be formed from a partially or selectively reflective material (e.g., half mirror, dichroic mirror, etc.) that transmits at least a portion of focused lightincident thereon through mirrorfor propagation toward array.

300 200 240 290 300 304 320 300 302 320 304 302 320 300 300 a a a As noted above, systemcan be used with LIDAR device, in addition to or instead of transmitterand system. In such implementations, systemmay emit lightfrom a same location (e.g., aperture) as the location at which systemreceives focused light(e.g., aperture). Because the transmit path of emitted lightand the receive path of focused lightare co-aligned (e.g., both paths are from the point-of-view of aperture, systemmay be less susceptible to the effects of parallax. In turn, a LIDAR device that employs systemcould generate a representation of the scanned scene (e.g., data point cloud, etc.) that is less susceptible to errors related to parallax.

300 300 It is noted that the sizes, positions, orientations, and shapes of the components and features of systemshown are not necessarily to scale, but are illustrated as shown only for convenience in description. It is also noted that systemmay include fewer or more components than those shown, and one or more of the components shown could be arranged differently, physically combined, and/or physically divided into separate components.

310 320 360 320 320 310 360 360 320 304 302 320 310 360 320 310 304 320 330 a a a a In a first embodiment, the relative arrangement of array, aperture, and waveguidecan vary. In a first example, opaque material(and thus aperture) can be alternatively disposed between arrayand waveguide. For instance, waveguidecan be positioned adjacent to an opposite side of opaque material, while still transmitting emitted lightalong a path that overlaps the propagation path of focused lighttransmitted through aperture. In a second example, arraycan be alternatively disposed between waveguideand opaque material. For instance, arraymay include an aperture (e.g., cavity, etc.) through which emitted lightpropagates toward aperture(and lens).

310 In a second embodiment, arraycan be replaced by a single light detector rather than a plurality of light detectors.

360 320 360 320 360 320 360 320 320 a c a a In a third embodiment, a distance between waveguideand aperturecan vary. In one example, waveguidecan be disposed along (e.g., in contact with, etc.) opaque material. For instance, sidemay be substantially coplanar with or proximal to aperture. However, in other examples (as shown), waveguidecan be positioned at a distance (e.g., gap, etc.) from opaque material(and aperture).

300 330 320 360 300 300 In a fourth embodiment, systemcould optionally include an actuator that moves lens, opaque material, and/or waveguideto achieve a particular optical configuration (e.g., focus configuration, etc.) while scanning the scene. More generally, optical characteristics of systemcan be adjusted according to various applications of system.

320 320 330 320 330 330 330 320 330 300 320 360 302 304 320 238 300 330 300 a a a a a In a fifth embodiment, the position and/or orientation of aperturecan vary. In one example, aperturecan be disposed along the focal plane of lens. In another example, aperturecan be disposed parallel to the focal plane of lensbut at a different distance to lensthan the distance between the focal plane and lens. In yet another example, aperturecan be arranged at an offset orientation relative to the focal plane of lens. For instance, systemcan rotate (e.g., via an actuator) opaque material(and/or waveguide) to adjust the entry angle of lightand/orinto aperture. By doing so, for instance, a controller (e.g., controller) can further control optical characteristics of systemdepending on various factors such as lens characteristics of lens, environment of system(e.g., to reduce noise/interference arriving from a particular region of the scanned scene, etc.), among other factors.

360 360 In a sixth embodiment, waveguidecan alternatively have a cylindrical shape or any other shape. Additionally, in some examples, waveguidecan be implemented as a rigid structure (e.g., slab waveguide) or as a flexible structure (e.g., optical fiber).

4 FIG.A 4 FIG.A 400 460 462 464 466 400 100 290 300 200 290 240 460 360 360 c illustrates a first cross-section view of a systemthat includes multiple waveguides,,,, according to example embodiments. For purposes of illustration,shows an x-y-z axis, in which the z-axis extends through the page. Systemmay be similar to systems,, and/or, and can be used with deviceinstead of or in addition to systemand transmitter. For example, the side of waveguidealong the surface of the page may be similar to sideof waveguide.

400 434 440 340 450 452 454 456 350 460 462 464 466 360 As shown, systemincludes an optical element; a transmitterthat includes one or more light sources similar to light source; a plurality of mirrors,,,, each of which may be similar to mirror; and a plurality of waveguides,,,, each of which may be similar to waveguide.

434 440 460 462 464 466 404 434 Optical elementmay be interposed between transmitterand waveguides,,,, and may be configured to redirect, focus, collimate, and/or otherwise adjust optical characteristics of emitted light. To that end, optical elementmay comprise any combination of optical elements, such as lenses, mirrors, cylindrical lenses, light filters, etc.

434 404 440 404 404 404 404 460 462 464 466 434 404 460 434 404 460 460 404 460 a b c d a a a In one example, optical elementmay comprise a cylindrical lens, and/or other optical element configured to (at least partially) collimate and/or direct light beams(e.g., emitted by transmitter) as light portions,,,toward waveguides,,,. In this example, optical elementmay transmit a relatively larger amount of energy from emitted light portioninto waveguideby collimating the light beams. Alternatively or additionally, in this example, optical elementmay direct emitted light portioninto waveguideat a particular angle of entry (e.g., less than the critical angle of waveguide, etc.) that is suitable for light beam(s)to be guided inside waveguide(e.g., via total internal reflection, etc.).

434 440 460 462 464 466 434 404 404 404 404 434 a b c d In the embodiment shown, optical elementcan be implemented as a single optical element interposed between transmitterand waveguides,,,. For example, optical elementcan be implemented as an optical fiber that is arranged as a cylindrical lens to at least partially collimate light beams,,,. In other embodiments, optical elementcan be alternatively implemented as multiple physically separate optical elements (e.g., multiple cylindrical lenses), among other possibilities.

440 404 340 304 440 Transmittermay be configured to emit lightsimilarly to, respectively, light sourceand emitted light. To that end, transmittermay include one or more light sources (e.g., laser bars, LEDs, diode lasers, etc.).

440 404 404 404 404 404 400 a b c d In a first embodiment, transmittermay comprise a single light source that transmits light. For example, each of light portions,,,may originate from a single light source. With this arrangement, for example, a single light source can be used to drive four different transmit channels of system.

440 440 404 404 404 404 a b c d In a second embodiment, a given light source in transmittercan be used to drive fewer or more than four transmit channels. For example, transmittermay include a first light source that provides light portions,, and a second light source that provides light portions,. In one implementation, a single light source can be used to drive eight transmit channels.

440 404 404 404 404 a b c d. In a third embodiment, transmittermay include a separate light source for driving each transmit channel. For example, a first light source may emit light portion, a second light source may emit light portion, a third light source may provide light portion, and a fourth light source may emit light portion

440 404 404 404 404 400 404 460 360 360 460 404 460 360 460 450 450 404 404 a b c d a a a b a a Regardless of the number of light sources in transmitter, emitted light beams,,,may then propagate along separate transmit paths toward an environment of system. By way of example, light beam(s)could be transmitted through a first side of waveguide(e.g., similar to sideof waveguide). Waveguidemay then guide lightin a lengthwise direction of waveguidetoward a second opposite side (e.g., similar to side) of waveguide, where mirroris located. Mirrormay then reflect guided lightout of the page (along z-axis), and toward a scene. Thus, light portionmay define a first transmit channel (e.g., LIDAR transmit channel, etc.) that is associated with the transmit path described above.

404 462 452 404 464 454 404 466 456 400 b c d Similarly, light beam(s)could define a second transmit channel associated with a transmit path defined by waveguideand mirror; light beam(s)could define a third transmit channel associated with a transmit path defined by waveguideand mirror; and light beam(s)could define a fourth transmit channel associated with a transmit path of light defined by waveguideand mirror. With this arrangement, systemmay emit a pattern of light beams toward a scene.

4 FIG.B 4 FIG.B 400 400 420 320 300 420 420 420 420 420 320 420 460 404 460 420 450 420 462 420 464 420 466 420 420 420 420 404 404 404 404 400 a b c d a a a a b c d a b c d a b c d illustrates a second cross-section view of system, where the z-axis is also pointing out of the page. As shown in, systemalso includes an opaque material, which may be similar to opaque materialof system. Opaque materialmay define a plurality of apertures, exemplified by apertures,,, and, each of which may be similar to aperture. For example, aperturemay be aligned (e.g., adjacent, overlapping, etc.) with an output end of waveguide(e.g., where lightexits waveguide). For example, aperturemay overlap mirrorin the direction of the z-axis. Similarly, aperturecan be aligned with an output end of waveguide, aperturecould be aligned with an output end of waveguide, and aperturecould be aligned with an output end of waveguide. Thus, each of apertures,,,may be co-aligned with respective transmit paths of emitted light portions,,,, and may thus define positions of the four transmit channels of system.

4 FIG.B 420 302 320 400 420 420 420 420 420 a b c d. Additionally, in some examples, focused light from the scene (e.g., propagating into the page in) may be projected onto opaque materialsimilarly to focused lightincident on opaque material. To that end, systemmay provide multiple receive channels associated with respective portions of the focused light projected on opaque materialat the respective positions of apertures,,,

420 420 420 420 a b c d For example, a first portion of the focused light transmitted through aperturecould be intercepted by a first light detector associated with a first receive channel, a second portion of the focused light transmitted through aperturecould be intercepted by a second light detector associated with a second receive channel, a third portion of the focused light transmitted through aperturecould be intercepted by a third light detector associated with a third receive channel, and a fourth portion of the focused light transmitted through aperturecould be intercepted by a fourth light detector associated with a fourth receive channel.

400 420 420 400 420 420 420 420 a b a b c d. With this arrangement, systemcan obtain a one-dimensional (1D) image (e.g., horizontal arrangement of pixels or LIDAR data points, etc.) of the scene. For instance, a first pixel or data point in the 1D image could be based on data from the first receive channel associated with aperture, and a second pixel in the 1D image could be based on data from the second receive channel associated with aperture. Additionally, with this arrangement, each transmit channel may be associated with a transmit path that is co-aligned (through a respective aperture) with a receive path associated with a corresponding receive channel. Thus, systemcan mitigate the effects of parallax by providing pairs of co-aligned transmit/receive channels defined by the locations of apertures,,,

460 462 464 466 400 4 FIG.A Although waveguides,,,are shown into be in a horizontal (e.g., along x-y plane) arrangement, in some examples, systemmay include waveguides in a different arrangement. In a first example, the waveguides can alternatively or additionally be arranged vertically (e.g., along y-z plane) to obtain a vertical 1D image (or line of LIDAR data points) representation of the scene. In a second example, the waveguides can alternatively be arranged both horizontally and vertically (e.g., as a two-dimensional grid) to obtain a two-dimensional (2D) image (or 2D grid of LIDAR data points) of the scene.

4 FIG.C 4 FIG.B 4 FIG.A 400 400 illustrates a third cross section view of system, in which the z-axis is also pointing out of the page. For example, one or more of the components of systemshown inmay be positioned above or below (e.g., along z-axis) one or more of the components shown in.

400 470 410 412 414 418 400 472 As shown, systemalso includes a support structurethat mounts a plurality of receivers, exemplified by,,,. Further, as shown, systemalso includes one or more light shields.

410 412 414 416 110 210 310 410 412 414 416 420 420 420 420 410 412 414 416 450 452 454 456 460 462 464 463 410 412 414 416 a b c d 4 FIG.B Each of receivers,,, andmay include one or more light detectors similar to the light detectors in any of arrays,, and/or. Receivers,,,may be arranged to intercept focused light that is transmitted, respectively, through apertures,,,(shown in). In one embodiment, receivers,,,may be positioned to overlap (e.g., in the direction of the z-axis), respectively, mirrors,,,(i.e., the output ends of waveguides,,,). In some examples, each of receivers,,,may include a respective array of light detectors connected in parallel to one another (e.g., SiPM, MPCC, etc.). In other examples, each receiver may include a single light detector.

470 410 412 414 416 410 412 414 416 470 410 412 414 416 Support structuremay include a printed circuit board (PCB) to which the light detectors of receivers,,,are mounted. By way of example, a first group of light detector(s) may define a first receive channel associated with receiver; a second adjacent group may define a second receive channel associated with receiver; a third adjacent group may define a third receive channel associated with receiver; and a fourth group may define a fourth receive channel associated with receiver. Alternatively or additionally, structuremay include a different type of solid material that has material characteristics suitable for supporting receivers,,,.

472 410 412 414 416 472 410 412 414 416 472 410 412 414 416 472 410 412 414 416 400 472 410 412 400 470 400 472 Light shield(s)may comprise one or more light absorbing materials (e.g., black carbon, black chrome, black plastic, etc.) arranged around receivers,,,. To that end, for example, light shield(s)may prevent (or reduce) light from external sources (e.g., ambient light, etc.) from reaching receivers,,,. Alternatively or additionally, for example, light shield(s)can prevent or reduce cross-talk between receive channels associated with receivers,,,. Thus, in this example, light shield(s)may be configured to optically separate receivers,,,, etc., of systemfrom one another. As shown, for instance, light shield(s)may be shaped in a honeycomb structure configuration, where each cell of the honeycomb structure shields light detectors of a first receiver (e.g., receiver) from light propagating toward light detectors in a second adjacent receiver (e.g., receiver). With this arrangement, systemmay provide for space-efficient placement of multiple arrays of light detectors (e.g., along a surface of structure) that are each aligned with a respective waveguide in system. Other shapes and/or arrangements of light shield(s)(e.g., rectangular-shaped cells, other shapes of cells, etc.) are possible.

4 FIG.D 400 460 460 460 360 360 360 400 430 432 474 476 478 474 476 480 482 484 a b a b illustrates a fourth cross-section view of system, where the y-axis is pointing through of the page. As shown, waveguideincludes sidesandwhich may be similar, respectively, to sidesandof waveguide. Further, as shown, systemalso includes a lens, a light filter, a plurality of substrates,, a materialdisposed between substratesand, a support structure, and a plurality of adhesives,.

430 330 430 420 402 420 420 420 420 402 402 420 460 410 460 430 410 430 404 450 420 430 a b c d a a a a 4 FIG.B 4 FIG.D 4 FIG.D 4 FIG.D Lensmay be similar to lens. For example, lensmay focus light from a scene toward opaque material. Respective portions of focused lightmay then be transmitted, respectively, through apertures,,,(shown in). Infor example, a portionof focused lightmay be transmitted through apertureonto waveguideand receiver. As shown in, waveguidemay be at a first distance to lens, and receivermay be at a second (greater) distance to lens. Further, as shown in, emitted light portionmay be reflected by mirrorthrough apertureand toward lens.

432 132 432 402 404 476 434 462 464 466 432 476 476 410 4 FIG.A 4 FIG.D Light filtermay be similar to light filter. For example, light filtermay include one or more devices configured to attenuate wavelengths of light(e.g., other than wavelengths of emitted light, etc.). In some examples, substrate(and filter) may extend horizontally (through the page; along the y-axis) to similarly attenuate light propagating toward waveguides,, and(shown in). As shown in, filtermay be disposed on a given side of substrate(e.g., between substrateand receiver).

432 476 474 476 400 402 402 410 476 432 432 400 432 476 432 476 410 412 410 412 414 416 472 a 4 FIG.C In another embodiment, filtermay be alternatively disposed on the opposite side of substrate(between substrates,), or at any other location in systemalong a propagation path of light(i.e., prior to detection of lightat receiver). In yet another embodiment, substratecan be formed from a material that has light filtering characteristics of filter. Thus, in this embodiment, filtercan be omitted from system(i.e., the functions of filtercan be performed by substrate). In still another embodiment, filtercan be implemented as multiple (e.g., smaller) filters that are each disposed between substrateand a respective one of the receivers. For instance, a first filter can be used to attenuate light propagating toward receiver, and a second separate filter can be used to attenuate light propagating toward receiver, etc. Referring back toby way of example, each filter can be disposed in (or adjacent to) each of cells,,,, etc. of the honeycomb structure of light shield.

474 476 404 474 476 Substratesandcan be formed from any transparent material configured to transmit at least some wavelengths of light (e.g., wavelengths of light, etc.) through the respective substrates. In one embodiment, substratesandmay include glass wafers.

478 460 478 460 462 464 466 478 474 476 478 460 430 420 a Materialmay be formed from any optical material that has optical characteristics suitable for defining an optical medium around waveguide. For example, materialmay include a gas, liquid, or solid material having a lower index of refraction than an index of refraction of waveguide(and waveguides,,). In some examples, materialmay comprise an optical adhesive that couples substratesandto one another. In these examples, materialmay be configured to support waveguidein a particular position relative to lens(and/or aperture).

478 400 478 As noted above, in some examples, materialmay comprise an adhesive material that mechanically attaches two or more components of systemto one another. In one example, material(configured as an optical adhesive) can be disposed between two particular components in a liquid form, and may then cure to a solid form to attach the two particular components to one another. To that end, example optical adhesives may include photopolymers or other polymers that can transform from a clear, colorless, liquid form into a solid form (e.g., in response to exposure to ultraviolet light or other energy source).

478 476 478 478 460 478 460 460 478 460 460 460 478 400 474 478 474 476 478 474 476 As shown, materialmay be disposed between and in contact with substratesand. Additionally, as shown, materialis in contact with one or more sides of waveguide. As noted above, materialmay have a lower index of refraction than the material of waveguide. The difference between the indexes of refraction at walls, sides, etc., of waveguideadjacent to materialmay cause guided light inside waveguideto internally reflect back into waveguideat the interface(s) between waveguideand material. In one implementation, the waveguides of systemcan be disposed on substrate, then materialcan be disposed on substrateand on the waveguides to support and/or maintain the waveguides in a particular relative arrangement, and then substratecan then be disposed on materialto attach substratewith substrate.

480 470 480 440 480 440 480 440 470 410 410 Support structuremay be formed from similar materials as structure(e.g., PCB, solid platform, etc.). As shown, structurecan be configured as a platform that mounts transmitter. For example, structurecan be implemented as a PCB on which one or more light sources (e.g., laser bar, etc.) of transmitterare mounted. To that end, structurecould optionally include wiring or other circuitry for transmitting power and signals to operate transmitter. In some examples, structuremay similarly include wiring and/or circuitry for transmitting power and/or communicating signals with receiverto operate receiver.

482 484 400 Adhesives,can be formed from any adhesive material suitable for attaching or otherwise coupling at least two components of systemto one another. A non-exhaustive list of example adhesive materials includes non-reactive adhesives, reactive adhesives, solvent-based adhesives (e.g., dissolved polymers, etc.), polymer dispersion adhesives (e.g., polyvinyl acetate, etc.), pressure-sensitive adhesives, contact adhesives (e.g., rubber, polycholoroprene, elastomers, etc.), hot adhesives (e.g., thermoplastics, ethylene-vinyl acetates, etc.), multi-component adhesives (e.g., thermosetting polymers, polyester resin-polyurethane resin, polypols—polyurethane resin, acrylic polymers-polyurethane resins, etc.), one-part adhesives, ultraviolet (UV) light curing adhesives, light curing materials (LCM), heat curing adhesives (e.g., thermoset epoxies, urethanes, polymides, etc.), and moisture curing adhesives (e.g., cyanoacrylates, urethanes, etc.), among others.

482 484 404 478 482 484 In some examples, adhesives,may comprise optical adhesive materials (e.g., materials that are transparent to at least some wavelengths of light), similarly to material. In other examples, adhesives,may comprise adhesive materials that are opaque and/or otherwise attenuate or prevent at least some wavelengths of light.

474 476 474 400 476 482 480 The assembly of components between (and including) substratesandmay together provide a “chip” assembly of the waveguides. For instance, substratemay define a top side of the chip assembly of system, and substrate, adhesive, and structuremay together define a bottom side of the chip assembly.

434 474 460 434 434 480 434 460 460 476 434 480 434 476 434 a Additionally, in the example shown, optical elementmay be disposed on a same surface of substrateon which waveguideis mounted. However, in other examples, optical elementcould be disposed on a different surface inside the chip assembly. In a first example, optical elementcould be mounted on structure. In a second example, optical elementcould be mounted on and/or attached to sideof waveguide. In a third example, although not shown, substratecould alternatively extend further horizontally (e.g., along x-axis) to overlap the location of optical element(e.g., structurecould be narrower horizontally, etc.). In this example, optical elementcould be disposed on substrate. In a fourth example, optical elementcould alternatively be disposed on another support structure (not shown) inside the chip assembly. Other examples are possible.

440 482 440 480 476 484 480 440 474 Additionally, transmittercould also be included inside the chip assembly. For example, as shown, adhesivemay couple (e.g., attach) transmitterand/or structureto substrate. Further, for example, adhesivemay couple or attach structure(and/or transmitter) to substrate.

440 434 400 400 400 By disposing transmitterand optical elementinside the chip assembly, systemcould shield and/or prevent damage to these optical components. Additionally, for instance, the chip assembly of systemcould support and/or maintain these optical components in a particular relative arrangement with respect to one another. By doing so, for instance, systemmay be less susceptible to calibration and/or misalignment errors that would occur if the particular relative arrangement of these components is inadvertently changed (e.g., if one of these components is moved differently than the other components).

4 FIG.A 4 FIG.C 462 464 466 474 460 400 474 472 As best shown in, in some examples, waveguides,,can be disposed on substratesimilarly to waveguide(e.g., arranged horizontally in the x-y plane). Further, in some examples, systemmay include additional (or fewer) waveguides in the same horizontal plane (e.g., disposed on substrate, etc.). Further, referring back to, these additional waveguides can similarly be aligned respective cells of the honeycomb-shaped light shield structure.

400 460 462 464 466 400 472 420 400 430 400 4 FIG.C In some examples, systemmay include waveguides mounted along a different horizontal plane than the plane in which waveguides,,,are located. The waveguides in the different horizontal plane could be aligned with additional receivers of system. The additional receivers, for instance, may be disposed within respective cells of the honeycomb-shaped light shield(s)shown in. Further, opaque materialmay include additional apertures aligned with these additional waveguides. With this arrangement, systemcan image additional regions of the focal plane of lensto provide a two-dimensional (2D) scanned image (or 2D grid of LIDAR data points). Alternatively or additionally, the entire assembly of systemcan be rotated or moved to generate the 2D scanned image of the scene.

420 430 430 420 64 400 400 In one example, opaque materialmay define a grid of apertures along the focal plane of lens, and each aperture in the grid may transmit light for a receive channel associated with a respective portion of the FOV of lens. In one embodiment, opaque materialmay comprise four rows ofapertures, where each row of horizontally (e.g., along y-axis) adjacent apertures is separated by a vertical offset (e.g., along z-axis) from another row of apertures. In this embodiment, systemcould thus provide 4*64=256 receive channels, and 256 co-aligned transmit channels. In other embodiments, systemmay include a different number of transmit/receive channels (and thus a different number of associated apertures).

400 400 294 296 400 420 420 420 420 238 400 400 400 2 FIG. a b c d In some implementations, systemcan be rotated about an axis while scanning a surrounding environment using the multiple transmit and receive channels. Referring back tofor example, systemcan be mounted on a rotating platform, similar to platform, that rotates about an axis (e.g., using actuator, etc.) while systemis transmitting light pulses and detecting reflections thereof (via apertures,,,, etc.). In this example, a controller (e.g., controller) or other computer system can receive LIDAR data collected using the co-aligned transmit/receive channels of system, and then process the LIDAR data to generate a 3D representation of the environment of system. In one implementation, systemcan be employed in a vehicle, and the 3D representation may be used to facilitate various operations of the vehicle (e.g., detect and/or identify objects around the vehicle, facilitate autonomous navigation of the vehicle in the environment, display the 3D representation to a user of the vehicle via a display, etc.).

4 4 FIGS.A-D 400 It is noted that the various sizes, shapes, and positions (e.g., distance between adjacent waveguides, etc.) shown infor the various components of systemare not necessarily to scale but are illustrated as shown only for convenience in description.

5 FIG. 5 FIG. 5 FIG. 4 FIG.C 500 500 100 290 300 400 500 400 illustrates a cross-section view of another system, according to example embodiments. Systemmay be similar to systems,,, and/or system, for example. For convenience in description,shows an x-y-z axis, where the y-axis is pointing out of the page. To that end, the cross-section view of systemshown inmay be similar to the cross-section view of systemshown in.

5 FIG. 500 510 520 520 532 534 540 550 560 560 560 570 572 574 576 578 580 582 584 410 420 420 432 434 440 450 460 460 460 470 472 474 476 578 480 482 484 400 502 502 504 504 402 402 404 404 a a b a a b a a a a. As shown in, systemincludes a receiver, an opaque material, an aperture, a light filter, an optical element, a transmitter, a mirror, a waveguidehaving sidesand, a support structure, one or more light shields, substrates,, material, support structure, and adhesives,, which may be similar, respectively, to receiver, opaque material, aperture, light filter, optical element, transmitter, mirror, waveguide, sidesand, support structure, light shield(s), substrates,, material, support structure, and adhesives,of system. To that end, focused light, focused light portion, emitted light, and emitted light portion, may be similar, respectively, to focused light, focused light portion, emitted light, and emitted light portion

As noted above, example systems herein may employ various arrangements of a lens, waveguide, and light detector(s) to define co-aligned transmit/receive paths.

400 420 460 430 404 402 420 4 FIG.D a a a a In a first example arrangement, system(as best shown in) includes apertureinterposed between waveguideand lens. In this example, both emitted lightand focused lightare transmitted through the same aperture, and may thus be associated with co-aligned transmit/receive paths.

500 520 560 510 500 502 520 504 520 500 560 550 520 530 502 504 502 520 504 502 504 502 5 FIG. a a a a a a a a a a a a a a In a second example arrangement, system(as shown in) includes apertureinterposed between waveguideand receiver. Thus, in system, focused lightis transmitted through aperture, but emitted lightis not transmitted through aperture. However, in system, an output end of waveguide(e.g., where mirroris located) may be interposed between apertureand lens(e.g., along the propagation path of focused light) to direct emitted lightfrom a same or similar point-of-view as focused lightthat is transmitted through aperture. Thus, the transmit path of emitted lightand the receive path of focused lightmay also be co-aligned (even though emitted lightand focused lightare not transmitted through the same aperture).

510 560 520 510 504 520 a a. In a third example arrangement, receivercould alternatively be disposed between waveguideand opaque material. For instance, receivermay include a cavity through which emitted lightcan propagate toward aperture

510 560 530 310 360 350 304 320 302 310 3 FIG.A a In a fourth example arrangement, receiverand a waveguidecould alternatively be positioned at a same distance to lens. Referring back tofor instance, one or more light detectors of array(e.g., one or more columns, rows, or other group of light detectors) could be replaced with waveguidesuch that mirrordirects emitted lighttoward the same apertureused for transmitting focused lighttoward array.

576 500 520 532 572 420 472 4 FIG.B 4 FIG.C In a fifth example arrangement, substratecan be alternatively omitted from system, and opaque material(e.g., pinhole array) can be instead disposed on filteror on light shield(s). Referring back tofor example, the aperture array defined by opaque materialcan be alternatively disposed onto the honeycomb baffle structure of light shield(s)shown in.

500 Other example arrangements are possible. Thus, in various examples, systemmay include more, fewer, or different components than those shown. Further, the arrangement of the various components may vary without departing from the scope of the present disclosure.

500 500 100 290 300 400 200 500 574 460 462 464 466 400 5 FIG. It is noted that some of the components of systemare omitted from the illustration offor convenience in description. For example, although not shown, systemmay also include multiple waveguides, and/or one or more other components such as any of the components of systems,,,, and/or device. For instance, systemmay include multiple waveguides disposed on substratein a horizontal arrangement (along x-y plane), similarly to waveguides,,,of system.

6 FIG. 6 FIG. 6 FIG. 4 FIG.A 600 600 100 290 300 400 500 200 240 290 600 400 illustrates another system, according to example embodiments. Systemmay be similar to systems,,,, and/or, and could be used with LIDAR deviceinstead of or in addition to transmitterand system. For convenience in description,shows an x-y-z axis, where the z-axis is pointing through the page. To that end, the cross-section view of systemshown inmay be similar to the cross-section view of systemshown in.

600 640 634 650 652 654 656 660 440 434 450 452 454 456 460 400 600 690 692 As shown, systemincludes a transmitter, an optical element, a plurality of mirrors,,,, and a waveguide, which may be similar, respectively, to transmitter, optical element, mirrors,,,, and waveguideof system. Further, as shown, systemalso includes reflectorsand.

640 604 660 634 440 404 460 434 Transmittermay emit lightinto waveguidevia optical element, similarly to, respectively, transmitter, light, waveguide, and optical element.

6 FIG. 660 660 660 660 660 600 660 460 462 464 466 b c d e As shown inhowever, waveguideincludes multiple output ends,,, and. Thus, for example, systemmay present an alternative embodiment for providing multiple transmit/receive channels by using a single waveguideinstead of using multiple waveguides,,,.

660 660 660 660 460 460 660 650 604 660 360 604 652 660 660 604 654 660 660 604 656 660 660 b c d e b b c c d e. For example, each of output ends,,,may be similar to sideof waveguide. Output endmay include a tilted mirror(disposed thereon) that reflects a first portion of emitted lightout of the page (e.g., through a given side of waveguide, similar to side). Similarly, a second portion of emitted lightcould be reflected by mirrorand transmitted out of waveguideat output end; a third portion of emitted lightcould be reflected by mirrorand transmitted out of waveguideat output end; and a fourth portion of emitted lightcould be reflected by mirrorand transmitted out of waveguideat output end

600 660 660 660 660 420 420 420 420 460 462 464 466 600 660 660 660 660 410 412 414 416 b c d e a b c d b c d e 4 FIG.B 4 FIG.C Additionally, although not shown, systemmay also include a plurality of apertures that at least partially overlap (along the z-axis) locations of output ends,,,, similarly to the arrangement of apertures,,,shown inrelative to output ends of waveguides,,,. Further, systemmay also include a plurality of receivers (not shown) that are co-aligned with the apertures (and thus with output ends,,,) similarly to receivers,,,of.

660 604 660 660 660 660 640 600 660 b c d e Thus, waveguidecan be used to distribute the energy from emitted lightinto four different transmit paths that are co-aligned with receive paths that overlap output ends,,,(e.g., in the direction of the z-axis). To that end, for instance, light sourcecan be used to drive four separate transmit channels of systemusing a single waveguideinstead of using four separate waveguides.

660 660 660 660 660 660 660 660 660 660 660 660 660 660 a b c d e a b c d e. For example, waveguidemay extend lengthwise from input endto output ends,,,. Further, as shown, waveguidemay include a first lengthwise portion ‘a’ that extends from input endto a second lengthwise portion ‘b’ of waveguide; the second lengthwise portion ‘b’ may extend from the first lengthwise portion ‘a’ to a third lengthwise portion ‘c’ of waveguide; and the third lengthwise portion ‘c’ may extend from the second lengthwise portion ‘b’ to output ends,,,

600 690 692 690 692 604 690 692 Additionally, systemmay include reflectors,that are arranged along opposite sides of the first lengthwise portion ‘a’. Reflectors,may be implemented as mirrors or other reflective materials that are configured to reflect wavelengths of emitted lightincident thereon. To that end, a non-exhaustive list of example reflective materials of reflectors,includes gold, aluminum, other metal or metal oxide, synthetic polymers, hybrid pigments (e.g., fibrous clays and dyes, etc.), among other examples.

690 692 690 692 604 660 690 692 604 604 660 604 660 604 660 660 660 660 b c d e. In one embodiment, reflectors,may include two parallel mirrors that are disposed on or adjacent to horizontal sides (e.g., along two parallel x-z planes) of first waveguide portion ‘a’. In this embodiment, reflectorsandmay together provide a homogenizer for emitted lightentering waveguide. For example, reflectors,may reflect emitted lightincident thereon (horizontally). As a result, the energy of emitted lightentering the second portion ‘b’ of waveguidemay be distributed more uniformly (i.e., homogenized) relative to the energy distribution of emitted lightat input end. By doing so, for instance, the energy of emitted lightcan be more uniformly distributed among the transmit channels associated with output ends,,,

600 660 604 660 604 In some embodiments, systemmay additionally or alternatively include reflectors disposed along other sides of waveguideto homogenize emitted lightvertically (e.g., along z-axis) as well as horizontally (e.g., along y-axis). For example, two parallel reflectors can be similarly arranged along two other sides of waveguide(e.g., sides that are parallel to the surface of the page) to homogenize emitted lightvertically.

604 690 692 In some implementations, emitted lightcan be homogenized in a variety of ways in addition to or instead of using reflectorsand.

600 690 692 604 690 692 In a first implementation, systemmay alternatively be configured without reflectorsand. For example, waveguide portion ‘a’ can be configured to have a sufficiently large length to allow homogenization of emitted lightvia total internal reflection even without reflectorsand.

660 690 692 608 660 a In a second implementation, one or more sides of waveguide(e.g., the sides on which reflectorsandare shown to be disposed and/or one or more other sides of waveguide portion ‘a’) can be alternatively or additionally tapered (e.g., tapered in or tapered out) to achieve better homogeneity of emitted lightin a shorter distance from sideto the second waveguide portion ‘b’ (e.g., shorter length of waveguide portion ‘a’ than in an implementation where the sides are not tapered).

600 604 604 660 604 a In a third implementation, systemmay include one or more mirrors that fold the path of emitted lightto achieve improved homogeneity of emitted lightin a shorter distance from sideto the second waveguide portion ‘b’ (e.g., shorter length of waveguide portion ‘a’ than in an implementation where the one or more mirrors are not present). Other implementations for homogenizing emitted lightare possible as well.

660 604 660 604 660 660 660 660 604 660 b c d e In some examples, as shown, a width of waveguidein the second lengthwise portion ‘b’ may gradually increase to control divergence (horizontally) of emitted lightthat is guided inside the second portion ‘b’ toward the third portion ‘c’. In this way, waveguidecan allow divergence of emitted light(horizontally) before guiding respective portions of the guided light toward output ends,,,. To that end, a length of the second portion ‘b’ may be selected to sufficiently allow emitted lightfrom first waveguide portion ‘a’ to diverge horizontally (e.g., in the direction of the y-axis) before being divided between the separate branches of waveguidein waveguide portion ‘c’.

660 604 660 660 660 660 660 660 660 660 660 660 660 660 660 b c d e b c d e. In the third lengthwise portion ‘c’, waveguidemay include a plurality of elongate members (e.g., branches, etc.) that extend away from one another to define separate transmit paths of respective portions of emitted lighttoward output ends,,,. In the example shown, waveguidehas four elongate members (e.g., branches, etc.). A first elongate member may correspond to the portion of waveguidethat extends from waveguide portion ‘b’ to output end; a second elongate member may correspond to the portion of waveguidethat extends from waveguide portion ‘b’ to output end; a third elongate member may correspond to the portion of waveguidethat extends from waveguide portion ‘b’ to output end; and a fourth elongate member may correspond to the portion of waveguidethat extends from waveguide portion ‘b’ to output end

660 604 660 604 660 604 660 604 660 604 650 652 654 656 b c d e With this arrangement, waveguidemay guide: a first portion of emitted lightvia the first elongate member toward end; a second portion of emitted lightvia the second elongate member toward end; a third portion of emitted lightvia the third elongate member toward end; and a fourth portion of emitted lightvia the fourth elongate member toward end. Further, for example, the respective portions of emitted light(guided via the respective elongate members) may then be reflected by mirrors,,,out of the page (e.g., in the direction of the z-axis) and toward a scene.

660 604 660 660 660 660 604 600 660 660 660 660 660 660 660 b b c d e c d e. Thus, with this arrangement, waveguidemay be configured as a beam splitter that splits portions of emitted lightinto several portions that are guided through a respective elongate member (e.g., branch) of waveguidetoward a respective output end. Alternatively or additionally, in some implementations, an elongate member can extend toward one or more additional elongate members (not shown) instead of terminating at an output end. For example, the first elongate member (associated with output end) may split the guided light therein into a plurality of branches (e.g., elongate members) that terminate with several output ends instead of the single output end. Thus, in this example, waveguidecan separate light(guided therein) into additional output ends to define additional transmit (and/or receive) channels of system. Further, in some examples, each of the additional branches extending from the first elongate member can be similarly split to more branches, etc. Similarly, the second, third, and/or fourth elongate members (respectively associated with output ends,,) can alternatively or additionally extend toward multiple branches of waveguideinstead of terminating, respectively, at output ends,,

660 660 Thus, it is noted that waveguideis shown to have one input end and four output ends only for the sake of example. Various alternative implementations of waveguideare possible without departing from the scope of the present disclosure. In one example, fewer or more elongate members may extend from waveguide portion ‘b’. In another example, one or more of the elongate members in waveguide portion ‘c’ can be split into multiple separate branches instead of terminating at a respective output end. Other examples are possible.

660 640 660 600 660 With any of these arrangements for example, waveguidecan thus be configured to drive multiple transmit channels using a same light source (e.g., light source). Further, in some examples, each of the transmit channels defined by waveguidemay transmit a respective light pulse at a substantially similar time (e.g., in a grid pattern, etc.) toward an environment of system(e.g., the respective light pulses may originate from a single light pulse that was split by waveguide).

660 660 604 660 660 660 660 660 604 660 660 660 600 660 130 230 330 430 530 630 600 b b b b b b b In some implementations, a cross-sectional area of at least part of an elongate member of waveguidemay gradually decrease in a direction of propagation of the guided light therein. For example, as shown, the first elongate member may have a gradually decreasing cross-sectional area near output end. With this configuration, for instance, the angular spread of rays in the first portion of emitted lightexiting waveguideat output endmay be larger than if there was no taper (i.e., gradually decreasing cross-sectional area) near output end. Alternatively, in another embodiment, the taper near output endcan be in an opposite direction (e.g., gradually increasing cross-sectional area of the first elongate member near output). In this embodiment, the angular spread of rays in the first portion of emitted lightexiting waveguideat outputmay be smaller than if there was no taper near output end. Thus, in some implementations, systemcan be configured to control the angular spread of rays in transmitted light signals by tapering side walls of waveguide. Through this process, for instance, the angular spread of the transmitted rays may be selected to match a numerical aperture of a lens (not shown), such as any of lenses,,,,, and/orfor instance, that directs the transmitted rays toward an environment of system.

660 660 660 660 660 660 660 660 600 c d e c d e As shown, the second, third, and fourth elongate members may also have gradually decreasing widths (e.g., walls of waveguidetapered in) near respective output ends,,. However, in line with the discussion above, the walls of waveguidenear output ends,,, could alternatively be tapered out (e.g., gradually increasing cross-sectional areas, etc.) to otherwise control the angular spread of output light beams depending on the particular configuration (e.g., lens characteristics, etc.) of system.

600 660 660 660 660 660 660 660 604 640 8 600 600 600 b c d e It is noted that systemmay include fewer, more, and/or different components than those shown. For example, although waveguideis shown to include four elongate members that define four transmit paths extending through four output ends,,,, waveguidemay alternatively include fewer or more output ends (and associated elongate members). In one embodiment, waveguidemay direct emitted lighttoward eight output ends. In this embodiment, a single light sourcemay drive eight separate transmit channels (co-aligned withcorresponding receive channels) of system. Further, in this embodiment, systemmay include 32 waveguides coupled to 32 light sources. Thus, in this embodiment, systemmay define 32*8=256 co-aligned transmit/receive channels that are driven using 32 light sources (e.g., lasers, etc.). Other configurations are possible.

7 FIG. 700 700 100 290 300 400 500 600 200 700 702 708 is a flowchart of a method, according to example embodiments. Methodpresents an embodiment of a method that could be used with systems,,,,,, and/or device, for example. Methodmay include one or more operations, functions, or actions as illustrated by one or more of blocks-. Although the blocks are illustrated in a sequential order, these blocks may in some instances be performed in parallel, and/or in a different order than those described herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and/or removed based upon the desired implementation.

700 700 7 FIG. In addition, for methodand other processes and methods disclosed herein, the flowchart shows functionality and operation of one possible implementation of present embodiments. In this regard, each block may represent a module, a segment, a portion of a manufacturing or operation process, or a portion of program code, which includes one or more instructions executable by a processor for implementing specific logical functions or steps in the process. The program code may be stored on any type of computer readable medium, for example, such as a storage device including a disk or hard drive. The computer readable medium may include a non-transitory computer readable medium, for example, such as computer-readable media that stores data for short periods of time like register memory, processor cache and Random Access Memory (RAM). The computer readable medium may also include non-transitory media, such as secondary or persistent long term storage, like read only memory (ROM), optical or magnetic disks, compact-disc read only memory (CD-ROM), for example. The computer readable media may also be any other volatile or non-volatile storage systems. The computer readable medium may be considered a computer readable storage medium, for example, or a tangible storage device. In addition, for methodand other processes and methods disclosed herein, each block inmay represent circuitry that is wired to perform the specific logical functions in the process.

702 700 340 304 360 360 704 700 360 706 700 350 360 304 320 330 398 708 700 330 302 310 a b c a 3 3 FIGS.A andB At block, methodinvolves emitting (e.g., via light source) light (e.g.,) toward a first side (e.g.,) of a waveguide (e.g.,). At block, methodinvolves guiding, inside the waveguide, the emitted light from the first side to a second side (e.g.,) of the waveguide opposite the first side. At block, methodinvolves reflecting (e.g., via mirror) the guided light toward a third side (e.g.,) of the waveguide. In some examples, at least a portion of the reflected light may propagate out of the third side toward a scene. Referring back tofor example, reflected lightmay propagate through apertureand lenstoward the scene (e.g., object). At block, methodinvolves focusing, via a lens (e.g.,), light (e.g.,) propagating from the scene onto the waveguide and a light detector (e.g., any of the light detectors included in array, etc.).

The above detailed description describes various features and functions of the disclosed systems, devices, and methods with reference to the accompanying figures. While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent. The various aspects and embodiments disclosed herein are for purposes of illustration only and are not intended to be limiting, with the true scope being indicated by the following claims.